This cat looks like he is in a state of ecstasy from the look on his face. His eyes are shut while awake indicating contentment. But he looks more than content; he’s ecstatic. It seems as if the combination of the music and close contact with his human guardian has created this state of complete contentment.
We don’t know how music affects cats. You can buy cat music but I am not sure how effective it is and whether cats enjoy music. I wonder if, in this example, it is a combination of (a) close contact with his human companion and (b) the music being played by a person to whom the cat is close which results in this state pure pleasure. I sense that the music is a factor. However, to the cat the music may be interpreted as a sound from his human companion. The piano music and the person become synonymous to the cat. I am speculating. If that is the case the music becomes and extension of the person and it surrounds the cat making him unusually happy – in fact ecstatic.